Comparative study of the ditrophic interaction between Beauveria bassiana and Plutella xylostella.

In the present investigation, hyperparasitic interaction between B. bassiana, TM (MH590235) and P. xylostella was studied through scanning electron microscopy and chromatographic techniques. Dose-mortality responses showed an increase in mortality of larva with an increase in spore concentration. The LC50 value for B. bassiana isolate TM (MH590235) was 2.4 × 107 spores mL-1. The ditrophic interaction between B. bassiana and P. xylostella after 24 h revealed the adherence of conidia on stemmata, sensory setae, maxillary palpi and legs. After 48 h post-infection (hpi), germination of the conidia and appressorium formation was observed. Formation of hyphae and initiation of fungal networking was observed at 72 hpi. Complete ramification by mycelia and conidiogenesis of B. bassiana was observed over the mycosed cadaver after 168 hpi. Subsequently, typical sympodial conidiophores of B. bassiana bearing secondary spores were also observed. The metabolome profile of healthy larvae of P. xylostella revealed the presence of non-volatile organic compounds (NVOCs) like docosene, nonadecene, palmitic acid and heneicosane. However, the NVOC profile was different in the P. xylostella larvae hyperparasitized by B. bassiana. The metabolites present in the infected cadaver were phthalate esters, hydroxyquebrachamine and lactones.

DFT simulations and vibrational analysis of FT-IR and FT-Raman spectra of 2,4-diamino-6-hydroxypyrimidine.

Quantum mechanical calculations of energies, geometries and vibrational wavenumbers of 2,4-diamino-6-hydroxypyrimidine (2,4DA6HP) were carried out by using ab initio HF and density functional theory (DFT/B3LYP) method using 6-311G(d,p) basis set. The optimized geometrical parameters obtained by B3LYP method show good agreement with experimental X-ray data. The best level of theory in order to reproduce the experimental wavenumbers is B3LYP method with the 6-311G(d,p) basis set. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. A detailed interpretation of the infrared spectra of 2,4DA6HP was also reported. The calculated HOMO and LUMO energies show that charge transfer occurs in the molecule. The entropy of the title compound is also performed at HF/6-311G(d,p) and B3LYP/6-311G(d,p) levels of theory. The theoretical spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed.